Epigenetic variation in the Nigerian skull: sutural pattern at the pterion.

The variation of pterion articulation was assessed in 212 north-eastern Nigerian dried skulls. Four sutural variants were recorded. Sphenoparietal articulation was present in 82.1%, frontotemporal articulation in 23.6%, stenocrotaphia in 1.9% and epipteric articulation in 5.7% of the skulls. Symmetry of articulation was predominant in sphenoparietal (86.7%), frontotemporal (58.0%) and stenocrotaphia (100.0%) articulations. Epipteric articulation was 100.0% unilateral. In cases of unilateral presence, the occurrence on the right side was predominant for sphenoparietal (65.2%) and epipteric (66.7%) articulations. Frontotemporal articulation was more frequently seen on the left side of the skull (73.9%). These variants, when combined with some other non-metrical and metrical variants, may become useful anthropological tools for the identification of the north-eastern Nigerian skull.